Mobile concrete pump



1970 A. VAN DER PLAATS 53 MOBILE CONCRETE PUMP Filed Jan. 27, 1969 5 Sheets-Sheet 1 INVENTOR. 4/1/DEEW Der PZ/IJTS BY United States Patent ftice U.S. C1. 417-345 9 Claims ABSTRACT OF THE DISCLOSURE An improved concrete pump which is mounted on the bed of a truck and whch includes a pair of pumping cylnders, a first pair of hydraulic cylinders connected with and utilized to drive the pumping cylinders, a concrete receiving hopper, housings for connecting the hopper with the pump cylinders, ball valves in the housing for controlling the flow of concrete between the hopper and the pumping cylinders and for controlling the discharge of concrete from the pumping cylinders, a second pair of hydraulic cylinders for controlling the ball valves and various hydraulic components for comprising the hydraulic system utilized to control the operation of the pump. A11 of these operating elements and components of the concrete pump are mounted on and carried by an I-beam which is mounted on the truck bed so that its central longitudinal axis is aligned with the center line of the truck bed. The manner and arrangement of mounting these operating elements and components on the I- beam faciltate maintenance and/or replacement of the elements and components. The I-beam is also mounted so that the rear end of the Lbeam, and the hopper carried therewith, may be swung through a vertical are. Thus, durng operation of the pump, the rear end of the I-beam rests on the ground so that the height of the hopper is reduced so as to facilitate the feeding of concrete into the hopper from conventonal ready-mix trucks. The concrete pump also includes mechanical linkage arrangements for controlling and for providing substantially trouble-free, smooth operation of the pump.

BACKGROUND OF THE INVENTION This invention relates to an improved concrete pump, and more particularly, to an improved concrete pump mounted on the bed of a truck.

In the past, truck-mounted pumps have been used to pump concrete in construction work. These concrete pumps have usually included pumping cylinders, valves for controlling the flow of concrete to and from the pumping cylinders, hydraulic cylinders or other mechanical means for operating the pumpnig cylinders and a hopper into which the concrete to be pumped is fed from conventional ready-mix trucks.

One of the problems with the prior truck-mounted concrete pumps is that the operatng elements and components of the pump have been positioned and arranged so that maintenance and/or replacement of these elements and components is time consuming, and thus expensive. The inaccessibility of the elements and components makes even such a relatively frequent maintenance operation as changing the seals in the pumping cylinders a difficnlt and laborious task and one whch disables the pump for a significant amount of time.

Another problem with the prior truck-mounted concrete pumps is that the concrete receiving hopper is positioned at such a height that there is difficulty in feeding the concrete into the hopper from conventonal readymix trucks. In other words, the top of the hopper is substantially equal to the height of the discharge opening in the ready-mix truck so that the concrete from the 3,532,442 Patented Oct. 6, 1970 ready-mix truck cannot be readily fed by gravty down the chute=s carried by the ready-mix truck, but rather must be manually raked down the chutes into the hopper by workmen. This is time consuming and, in effect, reduces the practical pumping rate of these prior concrete pumps.

SUMMARY OF THE INVENTION In contrast to the prior truck-mounted concrete pumps, the improved concrete pump of the present invention has all its operatng elements and components mounted on and carried by a centrally located I-beam whch, in turn, is mounted on the truck bed. The I-bearn is positioned on the truck "so as to permit ready access to all the operating elements and components and, f need be, the entire I- beam and, of course, the elements and components mounted thereon, can be easily and quickly removed from the truck bed. This mounting of the elements and components of the pump on the I-beam facilitates maintenance and/or replacement of the elements and components and significantly reduces the time and labor required to maintain the improved concrete pump of the present invention.

In addition, the forward end of the I-beam is pivotably mounted on the truck bed so that the rear end of the I-beam, and the hopper carried therewth, may be swung through a vertical arc and so that the rear end of the I- beam may be rested on the ground durng operation of the improved pump of the present invention. This significantly reduces the height of the upper end of the hopper, and because of this there is a significant differential in height between the hopper and the discharge opening on conventional ready-mix trucks so that the concrete discharged from the ready-mix trucks may be readily fed, by gravity, into the hopper. This decrease-s the time required to discharge the concrete into the hopper from the ready-mix trucks and thus, in effect, increases the practical pump rate of the improved concrete pump while minimizing the size of the crew required to operate the pump.

The improved concrete pump of the present invention also includes relatively simple mechanical linkage arrangements which are utilized to control the operation of the pumpng cylinders and the operation of the hydraulic cylinders used to control the operation of the valves controlling the flow of concrete to and from the pumping cylinders. These linkage arrangements assure proper coordinated, sequenced operation of the valves and pumpng cylinders, and because of their relative simplicity, provides dependable, trouble-free operation of the improved concrete pump of the present invention.

Accordingly, it is a primary object of the present invention to provide an improved concrete pump which is mounted on the bed of a truck and wherein the operating elements and components of the pump are arranged and positioned so as to minimize the time, and thus the oost, of maintaining the improved pump.

Another object of the present invention is to provide an improved concrete pump in which all the operating elements and components of the pump are mounted on and carried by an I-beam which is centrally positioned on the bed of the truck so as to make the elements and components readily accessible for maintenance and/or replacement.

Still another object of the present invention is to provide an improved concrete pump of the type described in whch the I-bearn is mounted on the truck bed so that the rear end thereof may be swung through a vertical are. A related object of the present invention is to provide an improved concrete pump of the type described wherein the rear end of the I-beam may rest on and be supported by the ground during operation of the pump so as to minimize the height of the concrete receiving hopper carried by the rear end of the I-beam and so as to facili- 2 tate the feeding of concrete into the hopper from conventional ready-mix trucks; and wherein the rear end of the I-beam may be moved upwardly, away from the ground, when the pump is not in operation, so that the truck on which the mproved pump of the present invention is mounted may be driven to another location without difficulty.

A further object of the present invention is to provide an mproved concrete pump of the type described wherein the operation of the concrete pump is controlled by relatively simple, mechanical linkage arrangements which assure coordinated, sequenced operation of the pumping cylinders and the valves used to control the flow of concrete to and from the pumping cylinders.

These and other objects and features of the present invention will become apparent from the following description of the preferred embodiment of the invention taken in conjuncton with the drawings described hereinbelow.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an mproved concrete pump of the present nvention shown mounted on the bed of a truck.

FIG. 2 is a side view of the mproved concrete pump of the present invention shown mounted on the bed of a truck.

FIG. 3 is a vertical, cross-sectional view taken along lines 33 in FIG. 2.

FIG. 4 is a plan view of the mproved concrete pump of the present inventon shown mounted on the bed of a truck.

FIG. 5 is a schematic view of the hydraulic system utilized in connection with the mproved concrete pump of the present invention.

Throughout the figures of the drawings, lke reference numerals have been used to indicate like elements and components. The hydraulic fluid lines or conduits have not been shown in FIGS. 1-4 for the sake of clarity. Also, in the description of the preferred embodiment, reference is made to the terms rear, rearward and forward. These terms are used to facilitate description of the pump and its elements and components and refer to the forward and rear ends of the truck on which the pump is mounted.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1-4, an mproved concrete pump 11 of the present invention is shown mounted on the bed 12 of a truck 13. The truck 13 is of conventional design and construction except that the bed 12 has been modified as hereinafter described. The bed 12 includes on each side a number of compartments 14, 15 and 16, which may be used to store hydraulic fluid, cleaning water, tools and sections of hose or pipe which may be utilized to convey the concrete being pumped to a location remote from the truck 13. A control panel 17 is positioned adjacent to the left rear end of the bed 12, and the controls needed to regulate the operation of the pump 11 may be included in this panel. A large tank-compartment 18 is mounted on the forward end 19 of the bed 12 and may be used to store hydraulic fluid or tools.

A relatively large, steel I-beam 21 is mounted on the bed 12 of the truck and is positioned so that its central longitudinal axis is substantially aligned with the central longitudinal axes of the bed 12 and the truck 13. The I-beam 21 includes a central webb 22 and upper and lower flanges 23 and 24, respectively. At the forward end 25 of the I-beam, the web 22 and the upper flange 23 are cut away, as best shown in FIG. 2, for reasons hereinafter described.

A central portion 26 of the bed 12 is cut away except for the part underlying the compartment-tank 18, and the width of the portion 26 is greater than the width of the flanges 23 and 24 of the I-beam. A conventional, split journal hearing 27 is positioned adjacent t0 each of the side edges of the portion 26 and above and slightly forward of the axle of the rear wheels 28 of the truck 13. A shaft 29 has its ends journaled and supported in the bearings 27. The shaft 29 extends through an aperture formed in the web 22 of the I-beam 21, and supports the I-beam 21 for pivotable movement about the shaft, with the central longitudinal axis of the shaft 29, and thus the axis about which the I-beam 21 pivots, being perpendicular to the central longitudinal axis of the I- beam 21 and spaced forwardly from the center of the I-beam.

As best shown in FIGS. 2 and 3, a frame 30 is secured to the sides of the portion 26 and includes a cross Inember 31 which is substantially parallel to, but spaced to the rear of and slightly below, the axle for the rear wheels 28 of the truck 13. A conventional hydraulic cylinder 32 is pivota-bly connected at one end to the center of the cross member 31 and has its rod end 33 pivotably connected with the center of the bottom flange 24 of the I-beam 21. The cylinder 32 is mounted and positioned so as to be able to cause the rear end 34 of the I-beam 21 to be swung through a vertical arc about the shaft 29.

A ground-engaging foot 35 is secured to the lower flange 24 of the I-beam 21 adjacent to its rear end 34 so that when the rear end 34 of the I-beam 21 is in its lowerrnost position, the foot 35 contacts and rests on the ground. When the rear end 34 of the I-bearn 21 has been swung to its uppermost position, the foot 35 is spaced from the ground a suflicient distance to permit the truck 13 to be driven without difliculty. Also, when the I-bearn is in its uppermost or traveling position, a frame 36 is used to lock and hold the I-beam in this position. The frame 36 is mounted on the cross member 31 and contacts the bottom flange 24 when being used to look the I-beam in its uppermost or traveling position.

A pair of pumping cylinders 37 and 38 are mounted on the I-beam 21 so that they are positioned adjacent to the web 22 and substantially between the upper and lower flanges 23 and 24. The rear ends of the pumping cylinders 37 and 38 are positioned adjacent to the rear end 34 of the I-bearn 21, and the cylinders 37 and 38 are carried by and moved with the I-beam 21 as it is swung through its vertical arc. The pumping cylinders 37 and 38 include pumping pistons 39 and 41, respectively, as shown in FIG. 3, which are positioned for reciprocal movement in their respective pumping cylinders. The cylinders 37 and 38 may be made from cast stainless steel and may, for example, have a diameter of 11% inches with an eective stroke of the pistons 39 and 41 being 36 inches which permits the pump 11 to make fewer cycles for a given volume of concrete pumped.

A pair of conventional hydraulic cylinders 42 and 43 are mounted on opposite sides of the I-beam 21 so that the cylinders are positioned adjacent to the web 22 and sub stantially between the upper and lower flanges 23 and 24 of the Ibeam. T he rear ends of the cylinders 42 and 43 are positioned adjacent to the forward ends of the pumping cylinders 37 and 38, respectively. As shown best in FIG. 4, the cylinders 42 and 43 include power pistons 44 and 45, respectively, which are positioned for reciprocal movement in their respective cylinders. The piston 44 is connected by a rod 46 with the piston 39 and this piston is connected by a rod 47 with the piston 41 so that the pistons 39 and 44 and the pistons 41 and 45 move together as units. Actuating rods 48 and 49 are also connected with the pistons 44 and 45, respectively, and extend out the forward ends of the cylinders 42 and 43 for threasons herein after described.

A pair of substantially identical housings 51 and 52 are secured to the rear ends of the pumping cylinders 37 and 38, respectively. Discharge nozzles 53 and 54 are forrned as an integral part of the housings 51 and 52, respectively, and are adapted to be connected with pipe or hose sections which are used to convey the cement being pumped to a point located remote from the truck 13.

A concrete receiving hopper 55 is mounted on the upper ends of the housings 51 and 52. The hopper 55 is generally U-shaped in transverse cross section and has an open, upper end 56. Each of the housings 51 and 52 include a first passage whch interconnects its discharge nozzle with its associated pumping cylinder and a second passage interconnecting an opening in the bottom of the hopper 55 with the first passage.

As best shown in FIG. 4, conventional hall valves 57 and 58 are positioned within the housings 51 and 52, respectively, at the juncture of the first and second passages formed in the housings and are utilized to control the flow of concrete through these passages. The housings 51 and 52 and each of the ball valves 57 and 58 are designed so that when a valve is in a first position, communication is permitted, and thus concrete may flow, from the hopper 55 to the associated pumping cylinder and when the valve is in a second position, communication is permitted, and thus concrete may flow, from the assocated pumping cylinder to and through the associated discharge nozzle. Also, when a valve is in its first position, communication is blocked by the valve between the pumping cylinder and discharge nozzle, and likewise, when the valve is in its second position, communication is blocked by the valve between the hopper and the pumping cylinder. The ball valves 57 and 58 are arranged so that when one of the valves is in its first position, the other valve is in its second position and vice versa.

A pair of conventional hydraulic cylinders 59 and 60 are pivotably connected at one end with a flange 61 secured to the upper flange 23 of the I-beam 21 adjacent to the rear end 34 of the I-beam. The rod ends 62 and 63 of the cylinders 59 and 60, respectively, are pivotably connected with the cranks 62a and 63a, respectively, whch, in turn, are connected with the ball valves 57 and 58, respectively. Operation of the cylinders 59 and 60 control the positioning of the ball valves 57 and 58 and more specifical ly, the cylinders 59 and 60 are utilized to pvotably move the valves 57 and 58 from their first position to their second position and from their second position to their first position Relatively simple, mechanica] linkage arrangements are utilized to control the operation and sequencing of the hydraulic cylinders 42, 43, 59 and 60. Generally speaking, the operation of the valve actuating cylinders 59 and 60 is initiated by the completion of the stroke of the hydraulic cylinders 42 and 43, and the operation of the cylinders 42 and 43 is initiated by the completion of the movement of the ball valves 57 and 58, i.e., the re-positioning of the valves 57 and 58.

More specifically, a linkage 64 is mounted on the exterior of the housing 51 and is directly connected with the hall valve 57 such that the linkage 64 moves in response to and is pivoted through the same arc as the hall valve 57. The linkage 64 includes arms 65 and 66, which are disposed at an angle of approximately 90 with respect to each other. A pilot valve 67, having an associated actuat ing arm 68, is mounted on the housing 51 adjacent to the linkage 64. The length of the arms 65 and 66 of the linkage 64 is such that they contact the actuating arm 68 as they are moved during pivotable movement of the valve 57. The linkage 64 is positioned, relative to the pilot valve 67, whereby when the valve 57 is moved from its first position to its second position the arm 66 contacts and moves the handle 68 so that the pilot valve 67 is moved to a first position. When the valve 57 is moved from the second position back to the first position, the arm 65 contacts and moves the handle 68 so that the pilot valve 67 is moved to a second position. Further, when the valve 57 is again moved from the first position to the second position, the arm 66 again contacts and moves the handle 68 so that the pilot valve 67 is re-positioned in its first position. The linkage 64 is arranged so that the arms 65 and 66 contact the arm 68 just as the valve 57 is completing its movement. The pilot valve 67, and more specifically the position of the pilot valve, controls the operation of the cylinders 42 and 43, as hereinafter described.

The operation of the hydraulic cylinders 59 and 60 is controlled by a pilot valve 69 which is mounted on the lower flange 24 of the I-beam 21 adjacent to the forward end 25 of the I-beam. A transverse arm 70 is connected, at its center, with the pilot valve 69 such that the pivotable movement of the arm 70 about its center causes the pilot valve 69 to be moved between a first and a second position. The length of the arm 70 is such that the actuating rods 48 and 49, and more specifically, the ends 71 and 72 of the rods 48 and 49, respectively, may contact the ends of the arm 70 as the rods 48 and 49 are moved to their extended or most forward position. As best shown in FIG. 2, each of the ends 71 and 72 comprise a relatively large diameter washer 73 secured to the threaded end of the actuating rod by a bolt 74.

As described more fully hereinbelow, the cylinders 42 and 43 are arranged so that when the piston of one cylinder is being moved by fluid pressure in one direction, the piston of the other cylinder is moved in the opposite direction. The arm 71 is arranged so that when an actuating arm of cylinder 42 or 43 reaches its most extended or most forward position, it contacts the end of the trans verse arm 71 and pivots the arm about the valve 69, with the actuating rod 48 causing the pivoting of the arm 71 in a clockwise direction and the actuating arm 49 causing the pivoting of the arm 71 in a counterclockwise direction, as shown in FIG. 4. The pivotal movement of the arm 71 caused by the actuating rod 48 moves the valve 69 from its first position to its second position, while the pivotal movement of the arm 71 caused by the actuating rod 49 moves the valve 69 from its second position to its first position. As noted above, the pilot valve 69 controls the operation of the cylinders 59 and 60.

As shown schematically in FIG. 5, the hydraulic system 75 which is utilized to control the operation of the pump 11 includes a pump 76 and a sump 77. The pump 76, as shown in FIG. 2, is arranged to be driven by the drive shaft 78 of the truck 13 by means of a clutch 79. The pump 76 and clutch 78 both are of conventional design and manufacture. The hydraulic system 75 includes three dstinct but interconnected partsa first part for controlling the cylinders 42 and 43, a second part for controlling the cylinders 59 and 61 and a third part for controlling the cylinder 32.

With respect to the first part of the hydraulic system 75, the outlet of the pump 76 communicates through a line 01 conduit 81 and a branch line 82 with a conventional, manually operable valve 83. The valve 83 is connected with the sump 77 by a line 84 and with pilot valve 67 by a pair of lines 85 and 86. Lines 87 and 88 connect the pilot valve 67 with the opposite ends, respectively, of a conventional four-way valve 89 such that the diference in the pressure of the fluid in the lines 87 and 88 determine the position which the valve 89 assumes. Valve 89 is connected, through line 91, with the line 81, and thus the pump 76, and through lines 92 and 84 with the sump 77. The lines 93 and 94 connect the valve 91 with the opposite ends of the hydraulic cylinders 42 and 43, with the line 93 communicating with the war or left end of the cylinder 42 and the forward or right end of the cylinder 43, while the line 94 communicates with the forward or right end of the cylinder 42 and the rear or left end of the cylinder 43. Thus, movement of the valve 89 to a position wherein the line 93 is placed in communicaton with the pump 76 while the line 94 is placed in communication with the sump 77, causes the piston 44 in cylinder 42 to move forwardly or to the right, while causing piston 45 in cylinder 43 to move rearwardly or to the left. Conversely, when the valve 89 is shifted to its other position, the line 93 is placed in communication with the sump 77 while the line 94 is placed in communication with the pump 76. When the valve 89 is in its other position, the piston 44 7 in the cylinder 42 is caused to move rearwardly or to the left while the piston 45 in the cylinder 43 is caused to be moved forwardly or to the right.

As noted above, the position of the valve 89 depends on the difference in the pressure of the fluid in the lines 87 and 88, which in turn depends on the position of the pilot valve 67, assuming that the valve 83 has been opened so that the line 85 is placed in commnnication with the line 82 which is, in turn, in communication with the pump 76 while the line 86 is placed in communicaton with line 84 and thus with the sump 77. Movement of the pilot valve 67, as the result of movement of the handle 68, to its first position so that line 87 is placed in communication with the line 85 and the line 88 is placed in communication with the line 86, results in the valve 89 being moved to the position wherein the line 94 is placed in communication with the pump 76. Conversely, when the pilot valve 67 is moved to its second position, again as a result of the movement of the handle 68, the line 85 is placed in communicaton with the line 88 while the line 86 is placed in communication with the line 87, and thus valve 89 is moved to the second position wherein the line 93 is placed in communication with the outlet of the pump 76 while the line 94 is placed in communication with the sump 77.

Referring now to the part of the hydraulc system 75 which controls the operation of the cylinders 59 and 60, a manually operable valve 95 communicates with the pump 76 through the line 81 and a branch line 96 and with the sump 77 through the line 84. Valve 95 communicates with the pilot valve 69 through lines 97 and 98. Pilot valve 69 communicates through lines 99 and 101 with the opposite ends of a conventional fourway valve 102 in such a manner that the difference in the pressure of the fluid in lines 99 and 101 determines the positioning of valve 102. Line 103 connects valve 102. with line 81 which is, in turn, connected with the outlet of pump 76, and line 84 also connects valve 102 with the sump 77. Lines 104 and 105 interconnect the valve 102 with the ends of the cylinders 59 and 60, with the line 104 being connected with the forward or right end of cylinder 59 and the rear or left end of cylinder 60 and with the line 105 being connected with the rear or left end of cylinder 59 and the forward or right end of cylinder 60.

The part of the hydraulc system 75 which controls the cylinders 59 and 60 functions in substantially the identical manner as the part of the system 75 described in connection with cylinders 42 and 43. Thus, when the valve 95 is open so that the lines 97 and 98 are placed in communication with lines 96 and 84, respectively, the movement of the transverse arm 70 so that the valve 69 is moved to a first position causes the lines 97 and 98 to be placed in communication with lines 99 and 101, respec tively. This, in turn, causes the valve 102 to be moved to a positon wherein the line 104 is placed in communication with pump 76 through lines 81 and 103, while line 105 is placed in communication with the sump 77 through line 84. When the valve 102 is in this postion, the piston in cylinder 59 moves rearwardly or to the left while the piston in cylnder 60 moves forwardly or the the right. Likewise, when the arm 68 is pivoted in the opposite direction s as to move the valve 67 to its second position, the lines 97 and 98 are placed in communication with the lines 101 and 99, respectively, whereby the valve 102 is moved to its other position. In the other position, the line 104 is placed in communication with the sump 77 through the line 84 while the line 105 is placed in communication with the pump 76 throngh the lines 103 and 81. Thus, when the valve 102 is in its other position, the piston in cylinder 59 is moved forwardly or to the right, while the piston in cylinder 60 is moved rearwardly or to the left.

As noted above, movement of the pstons in cylinders 42 and 43 results in pivotal movement of the arm 70, and thus movement of the pilot valve 67, which in turn causes movement of the pistons in the cylinders 59 and 60. When the movement of the pistons in the cylinders 59 and 60 is completed, this results in movement of the handle 68, which in turn, results in movement of the pilot valve 67 as to again actnate the cylinders 42 and 43, but in the opposite direction.

The part of the hydraulc system 75 which controls the cylinder 32 includes a branch line 106 which connects the line 81, and thus the outlet of the pump 76, with a manually operable valve 107. The valve 107 is also con nected throngh the line 84 with the sump 77. Lines 108 and 109 connect the valve 107 with the -opposite ends of the cylinder 32. Thus, when the valve 107 is moved to a first position wherein the line 106 is placed in communication with line 108 and the line 109 is placed in communication with line 84, the rear end 34 of the I-beam 21 is moved downwardly so that the foot 35 contacts the ground. Conversely, when the valve 107 is moved to its second position wherein the line 106 is placed in communication with the line 109 and the line 108 is placed in communi cation with the line 84, the rear end 34 of the I-beam 21 is swung upwardly away from a ground contacting position.

The manually operable valves 83, 95 and 107, together with a pressure gauge 111 which indicates the pressure in line 82, and thus in line 81, may be located in the control panel 17. Other manually actuated controls for controlling the operation of the clutch 79 and the operation of the motor in the truck 13 may also be located in the panel 17. The valves and gauge used in the hydraulc system 75 are of conventonal design and manufacture.

The components of the hydraulc system 75, except for the pump 76, the valves 67, 69, 83, 95 and 107 and the gauge 111, are mounted on the upper flange 23 of the I-beam 21 and are covered and protected by a removable cover 112. As noted above, the fluid lines or conduits described in connection with FIG. 5 are not shown in FIG. 1-4 for the purpose of clarity, but to the extent possible these lines are secured to the I-peam 21 so that removal of the I-beam can be accomplished by unfastening the bearings and disconnecting lines 81, 108 and 109. Thereafter, the entire I-beam 21 with all the other elements and components of the pump 11 can be quckly and easily removed from the bed 12 of the truck so as to facilitate their maintenance and repar. Moreover, if the maintenance or repair problem is not serious enough to require removal of the I-beam 21 from the truck, the components and elements of the pump 11 are so arranged with respect to the truck bed 12 that they are easily accessible for maintenance.

OPERATION The operation of the pump 11 is as follows: The truck 13 is driven to a construction site. The rear end 34 of the I-beam 21 is lowered so that the foot 35 rests on the ground as a result of moving the valve 107 to its first postion. Concrete is then fed, by gravty, into the hopper from a ready-mix truck by means of the conventional chute used by ready-mix trucks. The operation of the pump 76 is begun by actuation of the clutch 79, which connects the pump 76 with the drive shaft 78 of the truck 13. Concrete in the hopper is then sucked into one of the pumping cylinders, for example cylinder 38, through the valve 58 which is positioned so as to permit the concrete to flow from the hopper 55 into the cylinder 38. When the piston 45 of the cylinder 43 reaches its most forward position, the end 72 of the actuating rod 49 causes the transverse arm 70 to pivot clockwise there by causing the pilot valve 69 to move from its first position to its second position. The pilot valve 69 then causes the cylinders 59 and to be operated, whereby the ball valves 57 and 58 are moved so that the valve 57 permts concrete to flow from the hopper into the cylinder 37 while the valve 58 prevents flow of concrete from the hopper 55 but permits the concrete in the cylinder 38 to be forced out of the housing 52 through the nozzle 54. When ths movement of the valves 57 and 58 has been completed, the linkage 64 causes the pilot valve 67 to be moved from its first position to its second position, thereby causing the cylinders 42 and 43 to again be operated. However, in contrast to their previous operation, the piston 45 in cylinder 38 is moved rearwardly while the piston 44 in cylinder 37 is moved forwardly whereby concrete is drawn into the cylinder 37 while the concrete is forced out of the cylinder 38. Again, when the piston 44 reaches its most forward position, the end 71 of the actuating rod 48 causes the arm 70 to pivot counterclockwise whereby the pilot valve 69 is moved from its second position to its first position. The pilot valve 69 then causes the actuation of the cylinders 59 and 60, but in the opposite direction to their previous movement. Thus, the valve 57 is again moved so that it blocks communication between the hopper 55 and the cylinder 37 while permitting communication between the cylinder 37 and the nozzle 53. Likewise, the valve 58 is again moved so that it permits communication between the hopper 55 and the cylinder 38 but blocks communication between the cylindeer 38 and the nozzle 54. This sequenced operaton of the pump 11 continues until a sufficient quantity of concrete has been pumped. When the pumping operation has been completed, the valve 107 is again moved to its position whereby the line 107 is placed in communication with the line 106 and thus in communication with the outlet of the pump 76 so that the rear end 34 of the I-beam 21 is raised from its ground-contacting position to its traveling position. Thereafter, the frame 36 may be put into position so as to support the I-beam 21 during travel and the pump 76 may be disengaged from the drive shaft 7'6.

Accordingly, and as noted above, the improved concrete pump of the present inventon hereinabove described includes the advantageous feature of having all its working or operating elements and components arranged about and mounted on a single I-beam which can be easily and quickly removed from the bed of the truck and which permits easy access to these elements and components so as to minirnize maintenance time. In addition, the rear end of the I-beam can be lowered to a position whereby it rests on the ground so as to facilitate the feeding of concrete into the hopper from conventional readymix trucks. Also, the mechanical linkage system utilized to actuateand control the operation of the hydraulic cylinders which are used to operate the pumping cylinders and position the ball valves is relatively simple and trouble-free but yet assures smooth, substantially vibrationless pumping action.

The inventon described herein may be embodied in other specific forms other than the embodiment described hereinabove without departing from the spirit or central characteristics of the inventon. The present embodiment, therefore, is to be considered in all respects as llustrative and not restrictive, the scope of the inventon being indcated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

I claim:

1. An improved concrete pump adapted to be mounted on the bed of a truck, comprising:

an I-beam having a central web portion and an upper and lower flange portions, the I-beam being mounted on the truck bed so that the central longitudinal axis of the I-beam is substantially aligned with the central longitudinal axes of the truck and truck bed and so that one end of the I-bear is adjacent to the rear of the truck bed;

first pumping cylinder means mounted on and carried by the I-beam and including a pumping piston positioned for reciprocal movement therein, the first pumping cylinder means being positioned adjacent to one side of the central web portion and substantially between the flange portions of the I-beam;

second pumping cylinder means mounted on and carried by the I-beam and including a pumping piston positioned for reciprocal movement therein, the second pumping cylinder means being positioned adjacent to the other side of the central web portion and substantially between the flange portions of the I-beam;

a hopper mounted adjacent to and substantially above the one end of the I-beam, the hopper having an open upper end for receiving the concrete to be pumped and having first and second discharge openings therein through which the concrete in the hopper may be discharged from the hopper;

conduit means connecting the first and second discharge openings in the hopper with the one ends of the first and second pumpng cylinder means, respectively, the conduit means including a first and second discharge nozzle and being arranged so that it is mounted on and carried by the pumpng cylinder means, with the hopper being mounted on and carried by the conduit means;

first and second ball valve means mounted in the conduit means, the first ball valve means being selec tively positionable in a first position wherein the first ball valve means permits concrete to flow from the first discharge opening into the first purnping cylinder means or in a second position wherein the first ball valve means permits concrete to flow from the first pumping cylinder means to and through the first discharge nozzle, and the second bal1 valve means being selectively positionable in a first position wherein the second hall valve means permits concrete to flow from the second discharge opening into the second pumping cylinder means or in a second position wherein the second ball valve means permits concrete to flow from the second pumping cylinder means to and through the second discharge nozzle;

first hydraulic cylinder means for selectively moving the first and second ball valve means from their first to their second positions, the hydraulic cylinder means being arranged so that when the first hall valve means isin its first position, the second ball valve means is in its second position and so that when the first bal] valve means is in its second position, the second ball valve means is in its first position;

second hydraulic cylinder means mounted on and carred by the I-beam and including a first power piston positioned for reciprocal movement therein, the second hydraulic cylinder means being positioned adjacent to the one side of the central web portion and substantially between the flange portions of the I- beam, having one end thereof positioned adjacent to the other end of the first pumping cylinder means and including rod means for interconnecting the pumping piston in the first pumping cylinder means with the first power piston so that the pistons move together as a unit; and

third hydraulic cylinder means mounted on and carried by the I-beam and including a second power piston positioned for reciprocal movement therein, the second hydraulic cylinder being positioned adjacent to the other side of the central web portion and substantially between the flange portions of the I-beam, having one end thereof positioned adjacent to the other end of the second purnping cylinder means and including rod means for interconnecting the pumping piston in the second pumping cylinder means with the second power piston so that the pistons move together as a unit.

2. The improved concrete pump described in claim 1 wherein the I-beam may be moved relative to the truck bed between a first position wherein the one end of the I-beam rests on the gronnd, and a second position wherein the one end of the I-beam is spaced above the ground.

3. The improved concrete pump described in claim 2 including means for pivotably mounting the other end of the I-beam on the truck bed so that the one end of the I-bearn may be moved through a vertical arc relative to the truck bed, and further including fourth hydraulic cylinder means mounted on the truck bed fo1 selectively moving the one end of the I-beam from its first position to its second position and from its second position to its first position.

4. The improved concrete pump described in claim 3 Wherein a ground contacting foot member is attached to the lower flange portion of the I-beam adjacent to the one end of the I-beam so as to provide a support for the one end of the I-beam when the one end of the I-beam is in its first position.

5. The irnproved concrete pump described in claim 1 Wherein each of the second and third hydraulic cylinder means includes an actuating rod means connected with and movable with the power piston between a first position wherein the actuating rod means projects from the other end of the hydraulic cylinder means and a second position Wherein the actuating rod means is substantially retracted within the hydraulic cylinder means; wherein a first pilot valve means is mounted on the I-beam adjacent to the other end thereof and adjacent to the path of travel of the actuating rod means of the second and third hydraulic cylinder means, with the actuatng rod means and the first pilot valve means being arranged so that each of the actuating rod means actuates the first pilot valve means when it is moved to its first position; and wherein the first pilot valve means controls the operation of the first hydraulic means.

6. The improved concrete pump described in claim 5 wherein a second pilot valve means is positioned adjacent to the at least one of the first and second ball valve means; Wherein the second pilot valve means controls the operation of the second and third hydraulic cylinder means; and wherein an actuator linkage means is connected with and moves with the one hall valve means so that the sec 0nd pilot valve means is actuated each times the one hall valve means is moved trom its first position to its second position and from its second position to its first position.

7. The improved concrete pump described in claim 3 wherein each of the second and third hydraulic cylinder means includes an actuating rod means connected with and movable with the power piston between a first position whercin the actuating rod means projects from the other end of the hydraulic cylinder means and a second position wherein the actuating rod means is substantially retracted Within the hydraulic cylinder means; wherein a first pilot valve means is mounted on the I-beam adjacent to the other end thereof and adjacent to the path of travel of the actuating rod means and the first pilot valve means being arranged so that each of the actuating rod means actuates the first pilot valve means when it is moved to its first position; and wheren the first pilot valve means controls the operation of the first hydraulic means.

8. The improved concrete pump described in claim 7 wherein a second pilot valve means is positioned adjacent to the at least one of the first and second ball valve means; wherein the second pilot valve means controls the operation of the second and third hydraulic cylinder means; and wherein an actuator linkage means is connected with and moves with the one ball valve means so that the sec 0nd pilot valve means is actuated each time the one hall valve means is moved trom its first position to its second position and from its second position to its first position.

9. The improved concrete pump described in claim 8 wherein a ground contracting foot member is attached to the lower flange portion of the I-bearn adjacent to the one end of the I-beam so as to provide a support for the one end of the I-beam when the one end of the I-beam is in its first position.

References Cited UNITED STATES PATENTS 5/1965 Schumann 103-49 6/ 1967 Turzillo et al. 10349 ROBERT M. WALKER, Primary Examiner U.S. C1. X.R. 

